March 20, 2025: Unexpected findings about dark energy, the psychology of shopping addiction, and the fight over placing digital advertisements in Earth's orbit. —Andrea Gawrylewski, Chief Newsletter Editor | | | • Astronomers are racing to protect the dark skies as private companies seek to place large advertisements in Earth orbit. | 6 min read | | | • Health secretary RFK, Jr. has repeatedly suggested that farmers should let bird flu spread through flocks. Experts explain why that's a dangerous idea. | 4 min read | | | DESI's 3D map of the universe can show how dark energy may have evolved over time. Earth is at the center in this animation, and every dot is a galaxy. DESI collaboration and KPNO/NOIRLab/NSF/AURA/R. Proctor | | | Yesterday, a survey by the Dark Energy Spectroscopic Instrument (DESI) released its first preliminary results. They indicate that dark energy in the universe may change over time, and may not be as constant as physicists assumed it was. DESI measures sound waves from the first few hundred thousand years after the big bang and maps the patterns of galaxies, capturing more than 200,000 in a night. It then sorts the galactic light out into a spectrum, revealing the relative age of different clusters of galaxies. The measurements suggest that dark energy has evolved (growing weaker) since the days after the big bang.
Why this matters: For nearly three decades, astronomers have believed that the universe is expanding faster and faster and that the acceleration of this growth is constant over time—driven by a mysterious force they call "dark energy," which scientists think constitutes about 70 percent of everything in the universe. This force was supposed to represent the steady vacuum energy of space that astronomers dubbed the "cosmological constant." But now it seems dark energy may not actually be constant, in which case it can't be the cosmological constant, in which case…what the heck is it?
What the experts say: Assuming the results stand, a changing dark energy could spark an era of "chaos cosmology," says Kevork Abazajian, an astrophysicist at the University of California, Irvine. To make sense of these new findings would require either uncovering an entirely new fundamental force or realizing that our universe has more than four dimensions. "No matter what, we are discovering new physics here," Abazajian says. "There's nothing in the standard physics that allows for an evolving dark energy." | | | The Dark Energy Spectroscopic Instrument (DESI) maps the universe by collecting spectra from millions of galaxies and quasars. Marilyn Sargent/Berkeley Lab | | | • Is there any benefit in kids doing chores around the house? Chief opinion editor Megha Satyanarayana at Scientific American recently asked an expert in childhood development about the science behind kids and chores. "The task of a child is to gain these developmental milestones, these skills," says Rebecca Scharf, at the University of Virginia Medical School. Her recent work shows that kids who do chores report feeling more accomplished, competent and happy. Even though they gripe about household tasks, "I think this can be very satisfying for a child as they gain new competencies," she says.| 5 min read | | | The future of Earth's orbit looks bleak. Junk and debris are already piling up (some 25,000 trackable items), and threaten to interfere with mission launches and satellite operations. Now imagine looking up into space on a summer's night and rather than seeing a sparkle of stars, a red and glaring banner ad for CocaCola streams across the sky. This isn't science fiction. | This newsletter is still evolving. Tell me what you think and if we can do better by emailing: newsletters@sciam.com. See you tomorrow. | —Andrea Gawrylewski, Chief Newsletter Editor | P.S. In Monday's newsletter, I erroneously said that a planned Texas-based project would be the world's first direct air capture carbon removal plant. In fact, it'll be the first direct air capture carbon removal plant to be powered directly by wind power. Several direct air capture carbon removal plants already exist. Mea culpa! | | | | Subscribe to this and all of our newsletters . | | | | Scientific American
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